Mike, wonderful bit of serendipity seeing this thread revived in the light of developments and updates in the Skype software.
Can't comment on the conference call facility yet but over broadband and laptop to laptop using a Logitech 2 usb headset I'm getting the most incredible clarity I've ever heard on any comms system. The entire Mac tribe making up our crew agree it is even better than the excellent operating system level chat program installed in all Apples.
PC to phone is also remarkably good with one caveat - as bandwidth goes down due to traffic/contention ratios or whatever Syke seems to hang onto the signal but a delay is introduced. Most folks cope but my experience is that the many on the other end of the line, especially the elderly, find the experience unpleasant and difficult.
Skype is obviously being constantly improved and developed. As far as I'm concerned, and as a permanent road warrior, it has become the comms utilty of choice.
Regards
Rob Lloyd